Catalytic dehydrogenation processes are commonly used for the production of light olefins by conversion from their corresponding paraffins. One specific application of this technology produces propylene from the conversion of propane. Propylene is one of the world's largest produced petrochemical commodities and is used, for example, in the production of polypropylene, acrylonitrile, acrylic acid, acrolein, propylene oxide, glycols, plasticizers, oxo alcohols, cumene, isopropyl alcohol, and acetone. Another specific application can be to produce butene from butane.
Typically, commercial process for catalytic dehydrogenation of propane includes a reactor section comprising four catalytic reactors in series wherein the propane undergoes dehydrogenation followed by a product recovery section. Such catalytic reactors unit used in catalytic dehydrogenation process commonly require maintenance shutdowns more frequently than desired because of inner and/or outer screen fouling in the reactors. The screen fouling leads to high differential pressure and maldistribution of flow. Often, either a localized void blowing event or a mechanical design limit is reached that requires that the unit be shutdown and the reactor screens cleaned/maintained. The shutdown is often about 20 to 35 days in duration with consequent lost production and execution costs. Without the issue of screen fouling, the time between turnaround could likely be increased very substantially. Existing efforts to modify process conditions to reduce the rate of fouling or alter the reactor internal design to eliminate or improve the screens have been largely unsuccessful to-date.
Therefore, there is a need for improved processes and apparatuses for efficiently to reduce the rate of screen fouling in such catalytic dehydrogenation process. There is a need for a process and an apparatus which allows extended run between costly turnarounds in such catalytic dehydrogenation processes. Other desirable features and characteristics of the present subject matter will become apparent from the subsequent detailed description of the subject matter and the appended claims, taken in conjunction with the accompanying drawings and this background of the subject matter.